CN106938601B - Electric automobile heat pump air conditioning system and control method thereof - Google Patents

Abstract

The invention discloses an electric automobile heat pump air conditioning system and a control method thereof, wherein the electric automobile heat pump air conditioning system comprises an electric compressor, an internal evaporator and an internal condenser which are arranged in an electric automobile room, an external condenser and an external evaporator which are arranged outside the electric automobile room, a battery cooling device and a water pump which are used for absorbing waste heat of a fuel battery, and an electromagnetic valve and a throttling electronic expansion valve which are used for switching and acquiring three working modes of a refrigerating mode, a heating mode and a defrosting and dehumidifying mode, so that the comprehensive adjustment of the indoor temperature and humidity of the electric automobile can be realized, the comfort in the automobile is improved, and the safe driving of the electric automobile is ensured. The heat pump air conditioning system of the electric automobile and the control method thereof realize continuous heating, avoid atomization of condensed water, solve the problem of safe driving caused by switching between the current heating mode and the defrosting mode, and improve the heating quantity and the heating efficiency of the system by absorbing the waste heat of the fuel cell.

Description

Electric vehicle heat pump air conditioning system and control method thereof

technical field

The invention relates to the field of electric vehicle air conditioning, in particular to an electric vehicle heat pump air conditioning system and a control method thereof.

Background technique

Fuel cell electric vehicles have no engine to provide waste heat for heating in winter, so the automotive air conditioning system is required not only to have the cooling function in summer, but also to undertake heating in winter. At present, the air conditioning system of fuel cell electric vehicles is mainly based on electric heating auxiliary air conditioning system. Since electric heating is used for heating in winter, the maximum heating COP is 1. Therefore, when the air conditioner operates in heating mode in winter, it needs to consume a lot of Electric energy is used for heating, which will greatly shorten the cruising range of electric vehicles.

In order to improve the heating efficiency of fuel cell electric vehicles for heating in winter, a heat pump air conditioning system is also added to fuel cell electric vehicles. However, due to the low heating efficiency of the heat pump air conditioner in a low temperature environment and the heat exchanger outside the vehicle is prone to frost in the heating mode, the air conditioner needs to be switched from the heating mode to the defrosting mode to defrost in time, and the interior of the vehicle will stop during the defrosting period. Heating, the temperature in the car drops and condensed water is generated at the same time, and the comfort in the car is poor; when the system switches from the defrosting mode to the heating mode, the condensed water on the heat exchanger in the air duct will evaporate quickly and atomize on the windshield. It poses a certain danger to driving, so the application of traditional heat pump air-conditioning systems is often limited.

Raising the temperature of the heat source can effectively solve the low-temperature heating efficiency problem of fuel cell electric vehicles. For fuel cell electric vehicles, the heat generated by the fuel cell is very large, and the electrical energy and thermal energy converted from chemical energy account for about half. If the waste heat of the fuel cell can be recycled to increase the temperature of the heat source, it can not only improve the working performance of the fuel cell, but also improve the heating capacity of the heat pump air-conditioning system, so as to achieve the purpose of energy saving and emission reduction.

Contents of the invention

In order to solve the above problems, the present invention provides an electric vehicle heat pump air-conditioning system and its control method, which solves the problem of low operating efficiency of the existing electric vehicle heat pump air-conditioning system under low temperature conditions by recycling the waste heat of the fuel cell to increase the temperature of the heat source. It improves the heating efficiency of the heat pump air conditioning system in winter, and at the same time solves the safety driving problem caused by the switching between the heating mode and the defrosting mode of the currently developed electric vehicle air conditioning system.

To achieve the above object, the present invention takes the following technical solutions:

A heat pump air-conditioning system for an electric vehicle of the present invention comprises an electric compressor, an internal evaporator and an internal condenser located in the interior of the electric vehicle, an external condenser and an external evaporator located outside the electric vehicle, and a fuel cell for absorbing A battery cooling device for waste heat and a water pump, the external evaporator includes a first fluid channel and a second fluid channel for heat exchange, the outlet end of the electric compressor is respectively connected to the inlet end of the internal condenser and the inlet end of the external condenser, A first solenoid valve is provided between the electric compressor and the external condenser, a third solenoid valve is provided between the electric compressor and the internal condenser, and the outlet ports of the internal condenser are respectively connected to the seventh solenoid valve The inlet port and the inlet port of the fourth solenoid valve, the outlet port of the seventh solenoid valve and the outlet port of the fourth solenoid valve are all connected to the inlet port of the sixth solenoid valve through the first fluid channel, and the outlet port of the sixth solenoid valve is connected to the outlet port of the electric compressor. The outlet port of the first fluid channel is also connected to the inlet port of the second solenoid valve, the inlet port of the second solenoid valve is also connected to the outlet port of the external condenser, and the outlet port of the second solenoid valve is connected to the internal evaporator The inlet end is connected, the outlet end of the internal evaporator is connected to the inlet end of the electric compressor, the inlet end of the battery cooling device is connected to the inlet end of the fifth solenoid valve through the second fluid channel, and the outlet end of the fifth solenoid valve is cooled with the battery through a water pump The outlet port of the device is connected.

The outlet port of the fourth solenoid valve is connected to the first fluid channel through the second dry filter.

The outlet end of the fourth solenoid valve is connected to the first fluid passage through the second throttling electronic expansion valve.

The outlet port of the sixth solenoid valve is connected to the inlet port of the electric compressor through the second gas-liquid separator.

The outlet port of the second solenoid valve is connected to the inlet port of the internal evaporator through the first filter drier.

The outlet port of the second solenoid valve is connected to the inlet port of the internal evaporator through the first throttling electronic expansion valve.

The fuel cell is connected to the electric compressor voltage input through an inverter.

A control method for an electric vehicle heat pump air-conditioning system of the present invention comprises the following steps:

Judging the operating state of the electric vehicle heat pump air-conditioning system, the operating state includes cooling mode, heating mode and defrosting and dehumidifying mode;

When the electric vehicle heat pump air-conditioning system is in cooling mode, open the first solenoid valve, the second solenoid valve and the first throttling electronic expansion valve, and close the third solenoid valve, the fourth solenoid valve, the fifth solenoid valve, the Six solenoid valves, seventh solenoid valve and second throttling electronic expansion valve;

When the electric vehicle heat pump air conditioning system is in the heating mode, open the third solenoid valve, the fourth solenoid valve, the fifth solenoid valve, the sixth solenoid valve and the second throttling electronic expansion valve, and close the first solenoid valve, The second solenoid valve, the seventh solenoid valve and the first throttling electronic expansion valve;

When the electric vehicle heat pump air conditioning system is in the defrosting and dehumidification mode, open the second solenoid valve, the third solenoid valve, the fifth solenoid valve, the seventh solenoid valve and the first throttling electronic expansion valve, and close the first solenoid valve, , the fourth solenoid valve, the sixth solenoid valve and the second throttle electronic expansion valve.

In the defrosting and dehumidification mode of the present invention, the refrigerant passes through the internal condenser, the external evaporator and the internal evaporator sequentially, and after being liquefied in the internal condenser, the refrigerant directly enters the external evaporator through the seventh solenoid valve to absorb the heat of the refrigerant at the outlet of the internal condenser Together with the waste heat of the fuel cell, the defrosting of the external evaporator is realized, and the air in the car is cooled to the temperature required for dehumidification through the internal evaporator, and the air after recovering condensed water is heated by the internal condenser, and then sent to the car cabin,

Compared with prior art, the present invention has following advantage:

1. The present invention can obtain three working modes of cooling mode, heating mode and defrosting and dehumidification mode by switching the solenoid valve and the throttling electronic expansion valve, which can realize the comprehensive adjustment of the temperature and humidity in the electric vehicle and improve the comfort in the vehicle;

2. In the heating working mode of the present invention, a battery cooling device for absorbing waste heat of the fuel cell is provided, which forms a heat releasing circulation system with the water pump, the fifth solenoid valve and the second fluid passage, and the liquid refrigerant enters the external evaporation The heater absorbs the heat of the circulation system to absorb the waste heat of the fuel cell, thereby improving the heating capacity and heating efficiency of the system, which is more energy-efficient than the existing air-conditioning system of electric vehicles, and can effectively extend the cruising range.

3. By adding an internal condenser and an external evaporator, in the defrosting and dehumidification mode, the present invention absorbs the heat of the refrigerant at the outlet of the internal condenser and the waste heat of the fuel cell to realize the defrosting of the external evaporator, while realizing continuous heating and avoiding It prevents the atomization of condensed water, ensures the safe driving of the car, solves the safe driving problem caused by the mutual switching between the heating mode and the defrosting mode of the electric vehicle air conditioning system developed at present, and ensures the safe driving of the car.

Description of drawings

Fig. 1 is a block diagram of an electric vehicle heat pump air conditioning system according to the present invention.

Explanation of reference numerals: 1. fuel cell; 2. inverter; 3. electric compressor; 4. first solenoid valve; 5. external condenser; 6. second solenoid valve; 7. first dry filter; 8. First throttling electronic expansion valve; 9. Internal evaporator; 10. First gas-liquid separator; 11. Third solenoid valve; 12. Internal condenser; 13. Fourth solenoid valve; 14. Second drying Filter; 15. Second throttling electronic expansion valve; 16. External evaporator; 17. Battery cooling device; 18. Fifth solenoid valve; 19. Water pump; 20. Sixth solenoid valve; 21. Second gas-liquid separation device; 22, the seventh solenoid valve.

Detailed ways

The present invention will be further described below in combination with specific embodiments.

Example:

A heat pump air-conditioning system for an electric vehicle as shown in Figure 1 includes an electric compressor 3, an internal evaporator 9 and an internal condenser 12 located inside the electric vehicle, an external condenser 5 and an external evaporator located outside the electric vehicle 16, and a battery cooling device 17 and a water pump 19 for absorbing waste heat of the fuel cell 1, the external evaporator 16 includes a first fluid channel and a second fluid channel for heat exchange, and the outlet end of the electric compressor 3 is connected to the The inlet end of the internal condenser 12 is connected to the inlet end of the external condenser 5, a first electromagnetic valve 4 is provided between the electric compressor 3 and the external condenser 5, and a solenoid valve 4 is provided between the electric compressor 3 and the internal condenser 12. There is a third electromagnetic valve 11, and the outlet end of the internal condenser 12 is connected to the inlet end of the seventh electromagnetic valve 22 and the inlet end of the fourth electromagnetic valve 13 respectively, and the outlet end of the seventh electromagnetic valve 22 is connected to the sixth electromagnetic valve through the first fluid passage. Solenoid valve 20 inlet port. Preferably, the outlet port of the fourth solenoid valve 13 is connected to the inlet port of the sixth solenoid valve 20 through the first fluid channel after passing through the second dry filter 14 and the second throttling electronic expansion valve 15 in sequence. Preferably, the outlet port of the sixth solenoid valve 20 is connected to the inlet port of the electric compressor 3 through the second gas-liquid separator 21, and the outlet port of the first fluid channel is also connected to the inlet port of the second solenoid valve 6, so The inlet end of the second electromagnetic valve 6 is also connected to the outlet end of the external condenser 5 . Preferably, the outlet end of the second electromagnetic valve 6 passes through the first dry filter 7 and the first throttling electronic expansion valve 8 in sequence, and then is connected to the inlet end of the internal evaporator 9, and the outlet end of the internal evaporator 9 is connected to the inlet of the electric compressor 3 The inlet end of the battery cooling device 17 is connected to the inlet end of the fifth solenoid valve 18 through the second fluid passage, and the outlet end of the fifth solenoid valve 18 is connected to the outlet end of the battery cooling device 17 through the water pump 19 .

The fuel cell 1 is connected to the voltage input terminal of the electric compressor 3 through the inverter 2, and is used to supply power to the electric compressor.

By switching the solenoid valve and the throttling electronic expansion valve, the system can obtain three working modes: cooling mode, heating mode and defrosting and dehumidification mode, which can realize the comprehensive adjustment of the indoor temperature and humidity of the electric vehicle and improve the comfort of the vehicle. performance, while ensuring the safe driving of electric vehicles. Under the three working modes, the working states of the internal and external evaporators and internal and external condensers are shown in Table 1:

Table 1

In the three working modes, the switching states of the solenoid valve and the throttling electronic expansion valve are shown in Table 2:

Table 2

The specific working principle is as follows. In the cooling mode, the first solenoid valve 4, the second solenoid valve 6 and the first throttling electronic expansion valve 8 are opened, and all other solenoid valves and the second throttling electronic expansion valve 15 are closed. After being compressed by the electric compressor 3, the refrigerant flows through the first solenoid valve 4 to the external condenser 5 to cool down and be liquefied. The liquefied refrigerant passes through the second solenoid valve 6, the first dry filter 7 and the first throttling electronic expansion valve. 8 enters the internal evaporator 9 for gasification. When the refrigerant gasifies, it absorbs the heat inside the car to realize refrigeration. The gasified gas returns to the electric compressor 3 through the first gas-liquid separator 10, thus completing the refrigeration cycle.

In the heating mode, the third solenoid valve 11, the fourth solenoid valve 13, the fifth solenoid valve 18, the sixth solenoid valve 20 and the second throttling electronic expansion valve 15 are turned on, and all other solenoid valves and the first solenoid valve are closed. Throttling electronic expansion valve 8, the refrigerant is compressed by the electric compressor 3 and enters the internal condenser 12 through the third solenoid valve 11 to liquefy and release heat, thereby heating the interior of the car. The liquefied refrigerant passes through the fourth solenoid valve 13, the second The second dry filter 14 and the second throttling electronic expansion valve 15 enter the first fluid channel of the external evaporator 16 to absorb heat. At the same time, the battery cooling device 17, the water pump 19, the fifth solenoid valve 18 and the second The two fluid passages form an exothermic circulation system, and water can be selected as the medium for the exothermic circulation system. In this way, the liquid refrigerant absorbs the waste heat of the fuel cell 1 and is vaporized, and the vaporized gas returns to the electric compressor 3 through the sixth solenoid valve 20 and the second gas-liquid separator 21 , thus completing the heating cycle.

In the defrosting and dehumidification mode, the third solenoid valve 11, the fifth solenoid valve 18, the seventh solenoid valve 22, the second solenoid valve 6 and the first throttling electronic expansion valve 8 are turned on, and all other solenoid valves and the first throttling electronic expansion valve 8 are closed. Two throttling electronic expansion valves 15, the refrigerant is compressed by the electric compressor 3 and then enters the internal condenser 12 through the third solenoid valve 11 to liquefy and release heat, thereby heating the interior of the car. The liquefied refrigerant enters through the seventh solenoid valve 22 The external evaporator 16 together realizes the defrosting of the external evaporator 16. After the refrigerant absorbs heat in the external evaporator 16, it passes through the second solenoid valve 6, the first dry filter 7 and the first throttling electronic expansion valve 8 to enter the interior. Evaporation in the evaporator 9 cools the air in the car to the temperature required for dehumidification, and the air after the condensed water is recovered is heated by the internal condenser 12 and then sent to the car room, avoiding the atomization of the condensed water and ensuring To ensure the safe driving of the car, the vaporized gas returns to the electric compressor 3 through the first gas-liquid separator 10, so as to realize the defrosting and dehumidification inside and outside the car respectively.

The present invention also provides a control method of the electric vehicle heat pump air-conditioning system according to the embodiment, the control method includes the following steps:

Judging the operating state of the electric vehicle heat pump air-conditioning system, the operating state includes cooling mode, heating mode and defrosting and dehumidifying mode;

When the electric vehicle heat pump air-conditioning system is in cooling mode, open the first solenoid valve 4, the second solenoid valve 6 and the first throttling electronic expansion valve 8, and close the third solenoid valve 11, the fourth solenoid valve 13, the first The fifth solenoid valve 18, the sixth solenoid valve 20, the seventh solenoid valve 22 and the second throttle electronic expansion valve 15;

When the electric vehicle heat pump air-conditioning system is in the heating mode, the third solenoid valve 11, the fourth solenoid valve 13, the fifth solenoid valve 18, the sixth solenoid valve 20 and the second throttling electronic expansion valve 15 are opened and closed The first solenoid valve 4, the second solenoid valve 6, the seventh solenoid valve 22 and the first throttling electronic expansion valve 8;

When the electric vehicle heat pump air conditioning system is in the defrosting and dehumidification mode, open the second solenoid valve 6, the third solenoid valve 11, the fifth solenoid valve 18, the seventh solenoid valve 22 and the first throttling electronic expansion valve 8, and close The first solenoid valve 4 , the fourth solenoid valve 13 , the sixth solenoid valve 20 and the second throttle electronic expansion valve 15 .

The above detailed description is a specific description of the feasible embodiment of the present invention. This embodiment is not used to limit the patent scope of the present invention. Any equivalent implementation or change that does not deviate from the present invention should be included in the patent scope of this case. middle.

Claims (8)

1. The utility model provides an electric automobile heat pump air conditioning system which is characterized in that, including locating electric compressor (3), inside evaporimeter (9) and inside condenser (12) in the electric automobile room, locate outside condenser (5) and outside evaporimeter (16) outside the electric automobile room, and be used for absorbing battery cooling device (17) and water pump (19) of fuel cell (1) waste heat, outside evaporimeter (16) are including carrying out first fluid channel and the second fluid channel of heat exchange, electric compressor (3) exit end is connected with inside condenser (12) entry end and outside condenser (5) entry end respectively, be equipped with first solenoid valve (4) between electric compressor (3) and outside condenser (5), be equipped with third solenoid valve (11) between electric compressor (3) and inside condenser (12), inside condenser (12) exit end is connected to seventh solenoid valve (22) entry end and fourth solenoid valve (13) entry end respectively, seventh solenoid valve (22) exit end and fourth solenoid valve (13) exit end all are connected to sixth solenoid valve (20) entry end through sixth fluid channel, still be connected with electric compressor (3) entry end and second solenoid valve (6) entry end, the inlet end of the second electromagnetic valve (6) is also connected with the outlet end of the external condenser (5), the outlet end of the second electromagnetic valve (6) is connected with the inlet end of the internal evaporator (9), the outlet end of the internal evaporator (9) is connected with the inlet end of the electric compressor (3), the inlet end of the battery cooling device (17) is connected to the inlet end of the fifth electromagnetic valve (18) through a second fluid channel, and the outlet end of the fifth electromagnetic valve (18) is connected with the outlet end of the battery cooling device (17) through a water pump (19).

2. An electric vehicle heat pump air conditioning system according to claim 1, characterized in that the outlet end of the second solenoid valve (6) is connected to the inlet end of the internal evaporator (9) through the first throttle valve (8).

3. An electric vehicle heat pump air conditioning system according to claim 2, characterized in that the outlet end of the fourth solenoid valve (13) is connected to the first fluid channel via a second throttling electronic expansion valve (15).

4. An electric vehicle heat pump air conditioning system according to claim 1, characterized in that the outlet end of the fourth solenoid valve (13) is connected to the first fluid channel via a second drier-filter (14).

5. An electric vehicle heat pump air conditioning system according to claim 1, characterized in that the outlet end of the sixth solenoid valve (20) is connected to the inlet end of the electric compressor (3) through a second gas-liquid separator (21).

6. The electric vehicle heat pump air conditioning system according to claim 1, characterized in that the outlet end of the second solenoid valve (6) is connected to the inlet end of the internal evaporator (9) through a first drier-filter (7).

7. Electric vehicle heat pump air conditioning system according to any of claims 1-6, characterized in that the fuel cell (1) is connected to the voltage input of the electric compressor (3) through an inverter (2).

8. A control method of the heat pump air conditioning system of an electric vehicle, characterized in that the heat pump air conditioning system of the electric vehicle is the heat pump air conditioning system of the electric vehicle according to claim 3, the control method comprising the following steps:

judging the running state of the heat pump air conditioning system of the electric automobile, wherein the running state comprises a refrigerating mode, a heating mode and a defrosting and dehumidifying mode;

when the electric automobile heat pump air conditioning system is in a refrigeration mode, a first electromagnetic valve (4), a second electromagnetic valve (6) and a first throttling electronic expansion valve (8) are opened, and a third electromagnetic valve (11), a fourth electromagnetic valve (13), a fifth electromagnetic valve (18), a sixth electromagnetic valve (20), a seventh electromagnetic valve (22) and a second throttling electronic expansion valve (15) are closed;

when the electric automobile heat pump air conditioning system is in a heating mode, a third electromagnetic valve (11), a fourth electromagnetic valve (13), a fifth electromagnetic valve (18), a sixth electromagnetic valve (20) and a second throttling electronic expansion valve (15) are opened, and a first electromagnetic valve (4), a second electromagnetic valve (6), a seventh electromagnetic valve (22) and a first throttling electronic expansion valve (8) are closed;

when the electric automobile heat pump air conditioning system is in a defrosting and dehumidifying mode, the second electromagnetic valve (6), the third electromagnetic valve (11), the fifth electromagnetic valve (18), the seventh electromagnetic valve (22) and the first throttling electronic expansion valve (8) are opened, and the first electromagnetic valve (4), the fourth electromagnetic valve (13), the sixth electromagnetic valve (20) and the second throttling electronic expansion valve (15) are closed.

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